The present invention relates generally to conveyor rollers for conveying products along a conveyor and, more particularly, to a mounting structure for rotatably mounting the rollers to the sidewalls of the conveyor. Although the invention is especially adapted for mounting motorized rollers, it may be used with rollers that are slaved to motorized rollers and to rollers driven from beneath such as by a belt or padded chain or the like. The invention may also be used with non-driven rollers.
Typically, conveyor rollers are mounted along opposite sidewalls of a conveyor. The rollers include shafts which extend longitudinally outwardly from each end of the roller and which are received by the sidewalls of the conveyor. These shafts are often non-circular, such as hexagonal shaped, such that rotation of the shafts relative to the sidewalls is substantially precluded when the shaft is received by a correspondingly shaped slot or hole in the sidewall.
Motorized rollers are typically implemented with a set of non-driven or slave rollers and may be interconnected with the slave rollers by a plurality of bands, such that rotation of the motorized roller causes a corresponding rotation of the slave rollers. The motorized rollers include a motor within the cylindrical portion of the roller, which causes relative rotation between the shaft portions and the cylindrical portion of the roller. Accordingly, when the shafts are secured to the sidewall of the conveyor, actuation of the motor within the roller causes the cylindrical portion of the roller to rotate. Because of the torque generated when the motorized roller is actuated, the shaft, submitted to the same torque, tends to rotate in the opposite direction from the roller, such that the sides of the non-circular shaft repeatedly impact the sides of the corresponding slot in the sidewall, thereby preventing rotation of the shaft. This repeated impact and relative movement may cause the edges of the shaft or of the hole or both to become worn or rounded over time, which leads to a looser fit of the shaft within the opening. Any looseness between the shaft and opening further results in squeaks or other noises and/or vibrations of the conveyor when it is operated. This eventually may result in greater maintenance costs and even loss of function, since the roller and/or the entire sidewall may have to be replaced when the wear and tear to the shaft and/or the opening in the sidewalls becomes excessive.
Because of the torque generated by the motorized rollers, it is generally preferred that the shafts be inserted through openings and not placed into slots whereby only a portion of the sidewall would contact and restrain the shafts. Therefore, in order to mount the rollers into the openings, the shafts may be spring loaded, such that the shaft may be pushed longitudinally inwardly into the roller to align the roller shaft with the openings and then released to allow the shaft to extend outwardly through the opening, thereby securing the shaft to the conveyor walls. While this may, at least initially, provide a mounting structure which substantially precludes rotation of the shaft, the spring loaded shafts are difficult to install and are costly additions to the rollers, since they require additional moving parts within the roller.
In order to improve upon the wear and tear and noise of the systems, one proposed device has implemented a tapered end to the shafts of the roller. When the tapered shafts are released, the spring loading of the shafts maintains a tight fit in the opening, since the opening is of a smaller size than the largest diameter of the tapered portion of the shaft. While this at least initially provides for a tighter fit between the roller shaft and the opening in the sidewall of the conveyor, over time the shaft and/or opening may wear and allow the shaft to extend further into the opening. The shaft may eventually extend outwardly to a point where the spring is no longer in compression, such that the shaft is no longer held tight to the opening in the sidewall. Therefore, while this device may delay a loose fit of the shaft within the openings, this does not avoid the requirement of eventually having to replace or repair the sidewalls of the conveyor and/or the roller as they become worm. Additionally, the proposed device still requires the spring loading of the shafts in the roller in order to properly mount the rollers to the conveyor.
Additional issues with most known mounting schemes is that they include fixed openings in the sidewalls of the conveyor. If a roller is to be mounted at an angle or skewed relative to the sidewalls of the conveyor, special openings must be cut or formed to accommodate such a mounting orientation. Similarly, special mounting openings are required if the roller is a tapered roller, where the shaft at the wider end of the roller must be mounted at a level below the opposite end, in order to maintain a substantially level conveying surface. Accordingly, if the conveyor is to be modified to implement skewed or tapered rollers, the sidewalls would have to be modified to accommodate such a mounting orientation or replaced with new sidewalls with the appropriate mounting locations. Forming additional holes through the sidewalls may weaken the structural rigidity of the walls, which may further shorten the life of the sidewalls. Also, replacing or modifying the sidewalls may add significant costs to the conveyor.
In order to avoid replacement of the entire sidewall of the conveyor each time the roller orientation may be modified, brackets have been proposed which are formed at angles, such that they may be installed to the sidewalls of the conveyor and provide a proper orientation for receiving the shafts of the skewed rollers therethrough. However, such brackets still require the axles of the rollers to be spring loaded and require replacement of the brackets whenever the orientation of the rollers is to be changed. Accordingly, multiple brackets are required and must be formed to a specific angle and properly installed at the appropriate location in order to mount the roller at the proper skew angle.
An additional proposed device provides a bearing block, which receives the shaft of the rollers and is pivotable about a vertical pivot axis, in order to be adjustable for receiving skewed rollers of varying degrees. However, such a mounting device still requires the shafts of the rollers to be spring loaded and is not adaptable for receiving tapered rollers without modifying the block and the sidewalls. Furthermore, the installation and removal of the shaft within the bearing blocks requires tightening and loosening a cap member such that the aperture through the bearing block may be tightened around the shaft of the roller or loosened for removal of the roller therefrom.
Therefore, there is a need in the art for an adjustable mounting structure for receiving and substantially securing the shaft ends of conveyor rollers, especially motorized conveyor rollers.
The present invention is intended to provide a mounting structure for receiving the shaft ends of a conveyor roller and pivotally mounting the roller to the sidewalls of a conveyor assembly. This is accomplished in a manner that allows an individual roller to be easily removed in order to, for example, replace the O-rings. Furthermore, the necessity for long brackets that must be separately positioned to the conveyor frame is avoided. Preferably, the shaft receiver or mounting structure is easily adaptable for use with skewed rollers and with tapered rollers, and further facilitates easy installation and removal of the rollers.
According to an aspect of the present invention, a roller shaft support secures a shaft end of a conveyor roller which extends laterally across a conveyor having opposite sidewalls extending generally along a direction of conveyance. The shaft support is interconnectable to the sidewalls of the conveyor such that the shaft support is pivotable about a first axis which extends generally along the direction of conveyance. Preferably, the shaft support is further pivotable about a second axis which extends generally perpendicular or normal to the direction of conveyance. Preferably, the conveyor roller is a motorized roller and the shaft support substantially precludes rotation of the shaft.
In one form, the shaft support comprises a mounting yoke and a receiving block, where the receiving block is pivotally mounted to the mounting yoke and the mounting yoke is pivotally mountable to the sidewalls of the conveyor. The receiving block is pivotable about the second axis and the mounting yoke is pivotable about the first axis.
According to another aspect of the present invention, a powered roller conveyor comprises a pair of opposite sidewalls, at least one motorized roller and at least one shaft support. The motorized roller comprises a shaft portion extending longitudinally outwardly from each end, a generally cylindrical roller surface, and a motor for rotating the roller surface relative to the shaft portions. The shaft support is adaptable to adjustably and pivotally mount at least one of the shaft portions to a sidewall of the conveyor. The shaft support substantially precludes rotation of the roller""s shaft portion relative to the shaft support. The shaft support is pivotable relative to the sidewall about a first axis which extends generally along the direction of conveyance of the conveyor. Preferably, the shaft receiver is pivotally interconnectable with the sidewalls about a second axis which is generally normal to the direction of conveyance.
In one form, the motorized roller is a tapered roller and the shaft receiver is adjustably mounted to receive the shaft portion at an appropriate angle. In another form, the motorized roller is mountable to the conveyor such that the roller is skewed with respect to the direction of conveyance. The shaft receiver at each end of the motorized roller is adjustably and pivotably mounted along the sidewalls such that the shaft receivers are spaced along the sidewalls and pivotable to receive the shaft portions at the appropriate angles.
These and other objects, advantages, purposes and features of this invention will become apparent upon review of the following specification in conjunction with the drawings.